Four medallists from the 2004 Athens Olympics have been disqualified and stripped of their medals after testing positive for anabolic steroids, the International Olympic Committee has announced.

Ukraine's shot put gold medallist Yuriy Bilonoh, Belarussian hammer silver medallist Ivan Tsikhan, Russian shot put bronze medallist Svetlana Krivelyova and Belarussian discus bronze medallist Irina Yatchenko have all been ordered to hand back their medals.

In the case of Krivelyova, she was only upgraded to bronze after compatriot Irina Korzhanenko, who won the event, tested positive for the banned steroid stanozolol at the time and was disqualified.

The cases came to light earlier this year when the IOC reanalysed a number of samples from the Athens Games in a bid to snare athletes who had avoided detection.

Tsikhan was thrown out of the London Olympics this year when his positive test from Athens was discovered.

Disciplinary hearings were held for the athletes over the weekend.